Holder said the policy change will be applied to low-level, non-violent suspects who have been charged but not yet tried, and to similar defendants who have been convicted but not sentenced.

"By reserving the most severe prison terms for serious, high-level, or violent drug traffickers or kingpins, we can better enhance public safety," Holder said in a speech Thursday before the Congressional Black Caucus Foundation Criminal Justice Issues Forum, where he announced the change. "We can increase our focus on proven strategies for deterrence and rehabilitation. And we can do so while making our expenditures smarter and more productive."

The directive does not affect offenders already sentenced or in prison.

Last month, Holder announced that, in future drug cases, low-level, non-violent suspects would no longer be charged with offenses that impose severe mandatory sentences. The new directive expands that effort, ordering U.S. attorneys to apply the policy retroactively.

The Justice Department's policy applies to offenders who have no ties to gang or large drug organizations, and those whose offenses did not involve the use of a weapon or violence. The guidelines also state that the offender cannot have sold drugs to minors or have a significant criminal history.

Appropriate use of statutory authority "will enable us to use our limited resources to incarcerate those who pose the greatest threat," Holder said.

The Justice Department also will work to promote and strengthen diversion programs such as drug rehabilitation and community service initiatives that can provide "more effective alternatives to incarceration for some who come into contact with our criminal justice system."

He also directed all U.S. attorneys to designate a prevention and re-entry coordinator in every district "to help more formerly incarcerated individuals successfully rejoin their communities, become productive members of society and strengthen crime-afflicted neighborhoods across the country."

"Common-sense criminal justice reforms can make a profound, positive difference in the lives of millions of people," Holder said.

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